The network layer, or OSI Layer 3, provides services to allow end devices to exchange data across the network. To accomplish this end-to-end transport, the network layer uses four basic processes:

Unlike the transport layer (OSI Layer 4), which manages the data transport between the processes running on each host, network layer protocols specify the packet structure and processing used to carry the data from one host to another host. Operating without regard to the data carried in each packet allows the network layer to carry packets for multiple types of communications between multiple hosts.

The animation in the figure demonstrates the exchange of data.